Latch mechanism



Dec. 10, 1968 w. c. BARNARD 3,415,961

LATCH MECHANISM Dec. 10, 1968 Filed Sept. 26, 1966 W. C. BARNARD LATCH MECHANISM 3 Sheets-Sheet 2 Dec. l0, 1968 w. c. BARNARD 3,415,961

LATCH MECHANISM s sh t Filed sept. 26, 1966 ets Shea 3 United States Patent O 3,415,961 LATCH MECHANISM Walter C. Barnard, St. Paul, Minn., assigner to Whirlpool Corporation, a corporation of Delaware Filed Sept. 26, 1966, Ser. No. 582,030 11 Claims. (Cl. 20G-61.64)

This invention relates to latch mechanisms and in particular to latch mechanisms such as for use in latching closures.

In cabinet structures such as dishwasher cabinet structures, the loading opening is conventionally selectively closed by a closure door pivotally mounted on the cabinet. In such apparatus, it is desirable to assure the positive sealing closure of the door before the spray apparatus is permitted to be actuated so as to preclude undesirable splashing of the dishwashing liquid outwardly through the opening at all times. Further, in such apparatus, it is desirable to provide a positive latching or the door in the closed position against vibration forces and the like which may be generated in the dishwashing operation. Further, in such apparatus, it is desirable to provide such latching means having means for facilitated operation thereof both in latching the closure in the closed position and permitting facilitated unlatching when desired. 1t is further desirable that the latching means be simple and economical of construction, while yet providing long trouble-free life.

The present invention comprehends an improved latching structure providing the desirable features discussed above in a novel and simple manner.

Thus, a principal feature of the present invention is the provision of a new and improved latching structure.

Another feature of the invention is the provision of such a latching structure having new and improved means for assuring the sealed closure of the cabinet opening before operation of an associated electrical switching means thereby to preclude undesirable operation of the apparatus at all other times.

A further feature of the invention is the provision of such a latching structure having new and improved means for biasing the latch to a latching position.

Still another feature of the invention is the provision of such a latching structure having new and improved means for facilitated manipulation thereof.

A further feature of the invention is the provision of such a latching structure having a switch actuator pivotally mounted on the latching means for improved control of associated switch means.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein:

FIGURE 1 is a side elevation of a dishwasher apparatus having a latching structure embodying the invention;

FIGURE 2 is a fragmentary enlarged vertical section illustrating the arrangement of the latching structure as the closure is being moved to the closed position;

FIGURE 3 is a fragmentary front elevation of the latching structure;

FIGURE 4 is a top plan view thereof;

FIGURE 5 is a fragmentary vertical section similar to that of FIGURE 2, but with the door disposed just short of the fully closed position;

FIGURE 6 is a fragmentary vertical section similar to that of FIGURE 5, but with the door in the fully closed position and the latch in latching engagement with the strike; and

FIGURE 7 is a fragmentary vertical section similar to that of FIGURE 6, but with the latching structure repositioned to release the door.

3,415,961 Patented Dec. 10, 1968 lCC In the exemplary embodiment of the invention as disclosed in the drawing, a dishwasher apparatus generally designated 10 is shown to include a cabinet 11 having a front wall 12 defining an opening 13 selectively closable by a closure door 14 pivotally mounted on the front wall 12 by suitable pivot means (not shown). As

shown in FIGURE 2, the door 14 may be hollow being defined by a front panel 15 and a rear panel 16. A latching structure generally designated 17 is disposed generally within the space 18 between the front panel 15 and rear panel 16 in the upper portion of the door. Structure 17 includes a latch 19' which is engageable with a strike 20 carried on the cabinet wall 11 for latching the door 14 releasably in the closed position of FIGURE 6. A seal 21 is provided on the front cabinet wall 12 for sealing engagement by a seating corner portion 22 of the rear door panel 16 in the closed position of the door shown in FIGURE 6. An electrical switch 23 is provided in space 18 to be operated by an actuator 24 of latching structure 17 upon such sealing engagement between door portion 22 and seal 21 and latching engagement between latch 19 and strike 20.

More specically, the door 14 is provided with a handle 25 for use in swinging the door pivotally between the open and closed positions thereof. Subjacent the handle 25, the front door panel 15 is provided with an opening 26 forwardly through which projects a latch handle 27 comprising a forward extension of the latch 19. A bracket 28 is secured to the front door panel 15 by suitable means such as Screws 29 and includes a pair of side flanges 30 and 31, flange 30 being provided with a pivot opening 32 and flange 31 being provided with a similar pivot opening 33 axially aligned with opening 32. A crank rod 34 is provided at its opposite ends with coaxial pivot portions 35 received respectively in openings 32 and 33. The mid-portion of the crank rod 34 comprises a U-shaped portion including a bight 36 and a pair of link portions 37 at the opposite ends -of the bight 36 and joined to the pivots 35 respectively.

The latch 19 includes a Z-shaped mid-portion 38 extending under the crank rod bight 36, and three top Wall portions 39 extending about the upper portion of the crank rod bight 36 to effectively pivotally mount the latch 19 on the crank rod bight. Further, as shown in FIGURE 2, a coil spring 40 is provided with a first end 41 hooked to the bight 36 and an opposite end 42 connected to an upstanding ange 43 at the rear of the bracket 28 to extend the coil spring generally in the direction between the front panel 15 and rear panel 16 of the door. The

latch 19 further includes an arcuate web portion 44 ex- 1 tending rearwardly from the Z-shaped portion 38 and l end, the latch 19 includes a latching portion 47 including a forward catch 48 and a rearward camming flange 49.

The latch 19 further includes a downwardly projecting web 50 carrying at a lower portion thereof a pivot 51 on which is pivotally mounted a pivot portion 52 of the actuator 24. The switch 23 comprises a conventional snap action electrical switch including a push button actuator 53 projecting upwardly through an opening 54 in the bracket 28, the switch being mounted to a depending ange 63 of the bracket by suitable means such as screw 64. The actuator 24 defines a forward linger 55 adapted to engage the push button 53 for actuating the switch 23 as will be brought out more fully herefollowing.

As best seen in FIGURE 7, the strike 20 comprises an L-shaped member having a rear, turned portion 56 ernbracing the front edge of a portion of the front wall 12 defining a latching opening 57 in a horizontal upper por- 3 tion 58 thereof. At its opposite end, the strike 20` includes a turned portion 59 engaging the wall 12 in a suitable opening 60 provided therein adjacent the top of the cabinet.

The functioning of latching structure 17 is as follows. Assuming that the door is in the open position of FIG- URE 1, the coil spring 40 is, by virtue of its lateral biasing action, urging the latch 19 upwardly through an opening 61 in a forwardly turned upper portion 62 of the rear panel 16. In this normal position of the latch 19, the portion 47 will engage strike 20 as the door is swung upwardly and rearwardly, as indicated in FIGURE 2. The spring 40 is biasing the crank rod 34 in a clockwise direction at this time, so that the spring end `41 remains in the over-center position of FIGURE 2 notwithstanding a depression of the latch portion 47 as an incident of its engagement with the strike 20 and the further rearward movement of the door. Thus, in clearing the strike 20, the latch 19 effectively merely pivots on the bight 36 of the crank rod.

Upon rearwardly clearing the strike 20 as shownin FIGURE 5, the latch portion 47 may move freely upwardly through the opening 57 in the front cabinet wall 12 to dispose the catch portion 48 rearwardly of the strike. In the partially closed position of the door 14 as illustrated in FIGURE 5, the seating portion 22 of the rear panel 16 is in engagement with the seal 21. The engagement of the camming portion 46 of the actuator 24 causes a pivoting of the actuator about pivot 51, but as the pivot 51 is in a relatively low position, the finger 55 of the actuator does not as yet sufficiently depress the push button 53 to operate the switch 23.

To complete the sealed closure of the cabinet opening 13, the latch handle 27 is now depressed as shown in FIGURE 6 thereby to pivot the latch 19 about the crank rod bight 36 and bring the catch 48 into engagement with the turned rear end 56 of the strike 20. Continued downward urging of the latch lever 27 now causes the latch to pivot about the strike portion 56 and pivot the crank rod bight 36 in a counterclockwise direction about the pivots thereby swinging the coil spring end 41 overcenter to below the pivots 35 and resiliently biasing the latch 19 to maintain the latched condition of FIGURE 6. At the same time, the latching forces cause the door 14 to move slightly further rearwardly to engage more forcibly the seal 21 and thus provide a further improved sealed closure of the opening 13.

The further downward depression of the latch lever 27 in swinging the latch 19 from the position of FIGURE 5 to FIGURE 6 further raises the pivot 51 so as to pivot the cam portion 46 of the actuator 24 about its point of engagement 64 with the strike 20. This pivotal movement of the actuator 24 causes the finger portion 55 thereof to swing downwardly against the switch push button 53 and thereby operate the switch 23. Thus, the operation of switch 23 by the actuator 24 is delayed until the sealing engagement of the door portion 22 with the seal 21 is effected. Thus, where the apparatus 10 comprises a dishwasher apparatus, the delayed actuation of switch 23 effectively precludes undesirable passage of dishwashing liquid outwardly through the opening 13. As the coil spring is effectively biasing the latch 19, it is further effectively biasing the pivot S1 and, therefore, the actuator 24 to the switch operating position of FIGURE 6 to maintain the switch push button 53 in the depressed condition as long as the door remains closed.

To open the door, the user merely lifts the latch lever 27, as shown in FIGURE 7, to pivot the latch lever firstly about the strike portion 56 and thus firstly swing the crank rod 34 about pivots 3S to dispose the bight 36 in the upper over-centered position as shown in FIGURE 7. This causes finger to release switch button 53 and thereby open the control switch 23 before the door seal is broken. Continued upward movement of the latch lever 27 causes the latch to pivot about the bight 36, thereby retracting the latch from the opening 57 to the position shown in FIGURE 7 wherein the latch clears the strike 20 so that the door 14 may then be swung forwardly from the opening 13. As seen in FIGURE 7 in the clockwise pivoted position of FIGURE 7, the latch portion 44 is being urged laterally against the coil spring 40, and thus upon the latch clearing the strike 20, when the lever 27 is released, the latch 19 is automatically repositioned in the normal position of FIGURE 2 for engagement of portion 47 with the strike 20 upon subsequent closing of the door 14.

Thus, spring 40 synergistically biases the latch in the latching position of FIGURE 6, positions the latch in the normal open position of FIGURE 2, and biases the actuator 24 in the switch actuating position of FIGURE 6. The crank rod 34 provides a unique control of the latching operation by virtue of its over-centered disposition of the bight 36 whereby spring 40 may provide the desirable multibiasing action discussed above. The latching structure 17 is extremely simple being comprised effectively of only two moving parts, the latch 19 and actuator 24 with the single spring 40 providing the different biasing functions, The operation of the latching structure is also eX- tremely simple being controlled by the single latching lever 27 which is operated by the normal hand motion of the user in opening the bottom pivoted door 14.

While I have shown and described one embodiment of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

The embodiment of the invention in which an exclusive property or privilege is claimed is defined as follows:

1. In a structure having means defining an opening and a closure for selectively closing said opening, means for latching said closure in an opening-closing position wherein the closure closes said opening, comprising:

means defining an edge portion means of said opening;

a latch movably carried on said closure having a latching portion;

means for moving said latching portion into latching engagement with said edge portion means when said closure is disposed in said opening-closing position;

a switch on said closure; and

an actuator movably carried on said latch arranged to engage said edge portion means and be moved thereby to operate said switch as an incident of disposition of said closure in said opening-closing position and the movement of said latch into latching engagement with said edge portion means.

2. The latching structure of claim 1 further including means for sealing said closure to said opening defining means when said closure is in said opening-closing position, said actuator being arranged to engage said edge portion means only when said closure is in sealing engagement with said sealing means.

3. The latching structure of claim 1 including spring means for biasing said `actuator -against said switch when latch is in said latching engagement with said edge portion means.

4. The latching structure of claim 1 wherein said actuator is pivotally carried on said latch.

5. The latching structure of claim 1 wherein said latch is pivotally carried on said closure.

6. In a structure having means defining an opening and a closure for selectively closing said opening, means for latching said closure in an opening-closing position wherein the closure closes said opening, comprising:

pivot means on said closure;

a link having a structure pivotally carried on said pivot means and having a portion spaced from said pivot means;

a latch movably carried on said closure;

a spring having a first portion connected to said link portion and a second portion; and

means on said closure supporting said second portion of said spring to urge said link pivotally about said pivot means in either of opposite directions from a center position and urge said spring laterally against said latch when said link is pivoted in one of said directions thereby to bias said latch to a latching position.

7. The latching structure of claim 6 wherein said spring comprises a coil spring.

8. The latching structure of claim 6 wherein said latch is pivotally mounted on said closure.

9. The latching structure of claim 6 wherein said latch is pivotally mounted on said link portion.

10. The latching structure of claim 6 wherein switch means are provided on the closure and an actuator is provided on said latch for actuating said switch means when said latch is disposed in the latching position and References Cited UNITED STATES PATENTS 7/1963 Scott et al. 7/ 1966 Dargene 20D-61.64 6/ 1967 Geiger et al.

ROBERT K. SCHAEFER, Primary Examiner.

M. GINSBURG, Assistant Examiner.

U.S. Cl. X.R. 

1. IN A STRUCTURE HAVING MEANS DEFINING AN OPENING AND A CLOSURE FOR SELECTIVELY CLOSING SAID OPENING, MEANS FOR LATCHING SAID CLOSURE IN AN OPENING-CLOSING POSITION WHEREIN THE CLOSURE CLOSES SAID OPENING, COMPRISING; MEANS DEFININF AN EDGE PORTION MEANS OF SAID OPENING; A LATCH MOVABLY CARRIED ON SAID CLOSURE HAVING A LATCHING PORTION; MEANS FOR MOVING SAID LATCHING PORTION INTO LATCHING ENGAGEMENT WITH SAID EDGE PORTION MEANS WHEN SAID CLOSURE IS DISPOSED IN SAID OPENING-CLOSING POSITION, A SWITCH ON SAID CLOSURE; AND AN ACTUATOR MOVABLY CARRIED ON SAID LATCH ARRANGED TO ENGAGE SAID EDGE PORTION MEANS AND BE MOVED THEREBY TO OPERATE SAID SWTICH AS AN INDIDENT OF DISPOSITION OF SAID CLOSURE IN SAID OPENING-CLOSING POSITION AND THE MOVEMENT OF SAID LATCH INTO LATCHING ENGAGEMENT WITH SAID EDGE PORTION MEANS. 